exam Maths Puzzle Numerical Ability

Can someone show me a graph that represents y = 2 tan 2x?

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exam Other Question

R=-0.075t + 3.85 can be used to predict the world record in the 1500-m run t years after 1930. Determine (in terms of an inequality) those years for which the world record will be less than 3.5 minutes. If f(x) = 4x - 3, find the following:
f(-1)

If f(x)= 5x -1, find the following:
f(a-2)

I do not understand either of these problems either. please help me I am lost, so lost with this stuff.
Thank you,
Zack